IP based voice transmission technology is a flexible, simpler and a cost effective implementation of voice transmission. It provides a real convergence of various networks. This voice transmission technology does not support a quality that is equivalent to digitized voice, which is available in the existing PSTN networks. In addition to this, data network vulnerabilities affect the VOIP service causing a drop in the utilization of voice communication. In this paper, the quality of service for voice calls is ensured with the integration of CAC mechanism with the bandwidth link utilization which makes an estimation of the demanded bandwidth. In terms of security, prevention of ARP cache poisoning attack is achieved by use of the signed MAC address response in local area networks. It makes the network confident that the admitted user is an authorized user and also it verifies that only the authorized users’ information is exchanged over the local area network. Also an approach that makes it difficult for the hacker’s to hack the data exchanged over the quality channel has been proposed.